Method of preparing a hydrocarbon



Patented Oct'. 14, 1941 METHOD OF PREPARING A HYDROCARBON OIL HAVING DRYING OIL CHARACTERIS- TICS Herbert M. Steininger, Kansas City, Mo., and Roy J. Diwoky, Chicago, Ill., assignors to Standard Oil Company, Chicago, 11]., a corporation of Indiana No Drawing. Application July so, 1938,

Serial No. 222,116

3 Claims. (01. 196-50) This invention relates to drying oils and in particular to drying oils obtained from hydrocarbon oil.

It has been known heretofore that drying oils suitable for use in paints and varnishes could be obtained from various fractions of mineral oils, especially from various fractions of cracked oils and/or the polymers separated from such oils.

Thepresent invention is concerned with drying oils obtained from the residual tar resulting from the reforming of naphtha. In the production of gasoline, crude oil is first distilled under atmospheric pressures to produce, in addition to other fractions, naphthas and gas oil. The heavy naphthas so obtained constitute the major 'constituent of straight run gasoline, and the gas oil is usually cracked to obtain gasoline fractions and residual tar. More recently, clue to the necessity of producing gasolines having higher octane referred to in the petroleum refining art as reforming and as used herein and in the appended claims the term reforming refers to the treatment of distillates in the motor fuel vdistil- 35 lation range under conditions to produce gasolines having improved antiknock characteristics. The tar resulting from the reforming process is referred to as naphtha reformer tar.

It has been discovered that the naphtha reforming tars possess desirable fractions which are highly satisfactory as drying oils. The desired fractions of th reformer tar are particular overhead fractions, which are hereinafter more fully described, or the bottoms obtained by the reduction of naphtha reformer tar, particularly the reduced bottoms having Saybolt Universal viscosities at 210 F. ranging from about '70 seconds to about 300 seconds.

It has been further discovered that the siccative property of these fractions increases with the severity of the conditions of reforming; that is, as th octane number of the motor fuel obtained in the reforming process increases, the

The process of treat- 3 'ing heavy naphthas under severe conditions is reformer tar increases. For example, a reformer tar resulting from the reforming of heavy naphtha to a motor fuel having 69 octane number when reduced to a bottom having a Saybolt Uni- 5 versal viscosity at 210 F. of about 300 seconds had an iodine number, as determined by the Hanus method, of about 94, whereas a reformer tar resulting from the reforming of a heavy naphtha to a motor fuel having a 65 octane number when reduced to a bottom having a Saybolt that certain selected overhead fractions obtained during the reduction of the naphtha reformer tar also possess desirable siccative properties. It has been discovered that the drying property,

as indicated by the iodine number, of the various overhead fractions obtained during the reduction of naphtha reformer tar increases to a maximum with the increase in the viscosity of the overhead fractions, and then decreases as the viscosity of the overhead fractions continues to increase. This phenomenon is exemplified by the following data obtained from a reformer tar from the reforming of a heavy naphtha to a '65 octane number motor fuel. The reformer tar before reduction had an iodine number of 33. I

0 Viscosity-iodine number relationship of overhead fractions from reformer tar Saybolt viscosity at 100 F. of overhead fraction g z fig gi The data tabulated above were obtained by fractionating a reformed heavy naphtha into a series of very narrow cuts and determining the 4 viscosity and iodine number of each. The overhead fraction having a Saybolt viscosity at 100 F. of 35 seconds represents the seventh cut and about 2.8% by volume of the charge after about 80% by volume had been distilled over. The

50 fraction having a Saybolt viscosity at 100 F.

of 89 seconds represents the 24th out and about 0.28% by volume of the charge after about 90% by volume had been distilled over. These data show that even in a naphtha reformer tar from drying property of the selected fractions of the a octane number fuel there are overhead fractions which have highly desirable drying properties. These desirable overhead fractions from naphtha reformer tar represent from about 10% to about 15% of the total charge after about 80% by volume has been distilled over. The de- 5 sirable overhead cut may vary with the type of crude oil used, althoughfor most crude oils the desirable cut is the fraction which represents from about to about 20% of the total charge after from about 65% to about 85% by volume 10 has been distilled over. In general it will be found that the overhead fractions from a reformer tar which have Saybolt viscosities at 100 F. ranging from about 35 seconds to about 100 seconds and Hanus iodine numbers ranging from about '75 to 100 are th most suitable as drying oils.

In the course of the reduction of the naphtha reformer tar several bottom samples were taken which show the following properties:

Bottoms from reduction of naphtha reformer tar Iodine num- Saybolt viscosity at 210 F. (seconds) bet (mums) It will be observed that the bottoms resulting from the reduction of a naphtha reformer tar possess good drying properties.

In addition to the foregoing methods of obtaining petroleum fractions having drying oil characteristics, it has been discovered that similar products can be obtained from reformer tars by extracting the same with a suitable solvent having selective amnity for unsaturated compounds. For example, the extract obtained in the extraction of reformer tar with liquefied sulfur dioxide possesses desirable drying oil characteristics. Ex-- amples of the other solvents whichmay be employed are beta beta dichlorethyl ether, nitrobenzene, furfural, phenol, etc.

The reduced reformer tars or the high iodine number overhead fractions of reformer tars may be used as such as drying oils or they may be used in admixture with other drying oils, such as linseed oil China-wood oil, etc. Y

Although the invention has been described with respect to certain specific embodiments thereof, it is not intended to limit the scope thereto except as indicated in the appended claims.

We claim:

1. The method of preparing a hydrocarbon oil having drying oil characteristics which comprises reforming a heavy naphtha at a temperature ranging from about 980 F. to about 1250 F. and under pressures ranging from about atmospheric pressure to about 750 pounds per square inch, recovering a motor fuel distillate having an octane number of at least about and a reformer tar, and reducing said reformer tar to obtain at least two fractions, at least one of said fractions having a Saybolt Universal viscosity between about 35 seconds and about 100 seconds at 100 F. and a Hanus iodine number between about 75 and about 100. v

2. The method of producing a hydrocarbon oil having drying oil properties which comprises v reforming a heavy naphtha to produce a distillate having an octane number of at least about 65 and a residual tar, distilling said residual tar into overhead fractions while observing the iodine number of said overhead fractions until the iodine number of said overhead fractions after having risen to a maximum is observed to have fallen again as the distillation of said residuum is continued and recovering separately the overhead cuts having iodine numbers in the desired range.

3. The method of preparing a hydrocarbon oil having drying oil characteristics comprisingv reforming a heavy naphtha at a temperature ranging from about 980F. to about 1250 F. and under a pressure ranging from about atmospheric pressure to about 750 pounds per square inch, recovering a motor fuel distillate having an octane number of at least about 65 and a reformer tar, distilling said reformer tar to obtain a bottoms having a Saybolt Universal ,viscosity at 210 F. between about seconds and about 300 seconds and an overhead distillate having a Saybolt Universal viscosity at 100 F. between about 35 seconds and about 100 seconds and a Hanus iodine number between about and about 100.

,HERBERT M. S'IEININGER.

ROY J. DIWOKY. 

